Gallagher, should stay out for a couple games at least.
Further damage is caused when the head is contacted for the second time. The calcium has to be flushed from each brain cell through rest.
Calcium does solidifies on second contact, killing neurons that have taken on calcium after the first concussion.

Body checking should not be allowed along the boards. In the old days players held up when coming at a player who is along the boards and bent over…Otherwise the player would be dead due to no helmets being worn…..A much different game today….